Add subscription to Apple News
I already have a subscription to my local paper, but I can't see anywhere to enter it in Apple News. It keeps wanting me to subscribe to News+
I know the San Francisco Chronicle is available to Apple News+ subscribers. Certainly whether you had a subscription or not on the outside, if you subscribe to Apple News+, you could see it. But that’s not your question.
See especially “Subscribe to a publisher” here.
About individual channel subscriptions in Apple News - Apple Support